Automated cassette opening

ABSTRACT

A device for automatically opening a cassette includes a holding mechanism, an unlatching mechanism and an opening mechanism. The cassette to be opened has a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position. The holding mechanism is for receiving the cassette and securing the bottom portion of a received cassette. The unlatching mechanism includes an unlatching actuator coupled to a latch-engaging feature, the latch-engaging feature engaging the latch of the received cassette, the unlatching actuator capable of moving the latch-engaging feature to thereby move the latch engaged therein between the engaged position and the disengaged position. The opening mechanism includes an opening actuator and a top portion-engaging member, the top portion-engaging member engaging the top portion of the received cassette, the opening actuator capable of moving the top portion-engaging member to thereby move the top portion of the received cassette engaged thereby between the closed and the open position.

TECHNICAL FIELD

[0001] This invention relates to automated equipment for use in the handling of photomasks, and more particularly to methods and apparatus for automatically opening cassettes containing such photomasks.

BACKGROUND

[0002] Photomasks are commonly used in the production of microchips, integrated circuits, sensors, probe cards, calibration plates, etc. Each photomask is typically a substrate having a predetermined pattern of clear and opaque portions for selectively exposing an underlying workpiece. In order for the photomask to function effectively, it is important that its surface be kept clean, i.e., free from foreign particles that could undesirably obscure a clear portion of the substrate.

[0003] For example, in the production of integrated circuits, photomasks are often used to expose portions of wafers of semiconducting material to, e.g., UV (optical) rays and/or X-rays. The photomasks are typically plates of high purity quartz or glass with a pattern of clear and opaque areas, the opaque areas being generated, for example, by deposition of a layer of chrome on the plate's surface in the desired areas. Often several photomasks are required during the manufacturing process to generate the many layers of the circuit. As integrated circuits have become smaller and smaller, so too has the density of the pattern on each photomask used in the manufacturing process. As a result, it has become increasingly important to keep the photomasks clean, i.e., free from any foreign particles that may undesirably interfere during the exposure process. Notably, even a small dust particle on a single photomask used in production can render an entire, multi-layer integrated circuit unusable for its intended purpose.

[0004] In order to avoid contamination, the manufacturing process is typically carried out in a relatively sealed, “clean” environment in which automated equipment is commonly used for maneuvering the photomasks. The sealed environment may be equipped with an air filtration system for filtering any foreign particles from air circulated through the otherwise enclosed space during the manufacturing process. Such a vacuum system often incorporates an ultra low penetration air (ULPA) filtratrion system to prevent contamination by even very small particles.

[0005] In order to protect and keep a photomask clean when not in use, e.g., during periods of transport or storage, the photomask is typically placed in a cassette. To introduce the photomask to the automated manufacturing equipment described above, it is common for an operator to manually place the cassette within the clean environment and open the cassette to expose the photomask for handling by the automated equipment. This manual process of opening the cassette inevitably requires the operator to disrupt the otherwise relatively sealed, clean environment and physically intrude the environment to place and open the cassette. This means that when the cassette is initially opened, the clean environment is unsealed and the photomask within the cassette is exposed to any impurities that enter the disrupted area, including, e.g., any impurities which may be introduced by the operator.

[0006] It is desirable to minimize disruption of the clean manufacturing environment, especially when the photomask is exposed, e.g., when the cassette holding the photomask is open.

SUMMARY

[0007] In one aspect of the invention, an automated cassette opening device for opening a cassette is provided. The device opens and closes cassettes that have a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position. The cassette opening device includes a holding mechanism for receiving the cassette and securing the bottom portion of a received cassette; an unlatching mechanism including an unlatching actuator coupled to a latch-engaging feature, the latch-engaging feature engaging the latch of the received cassette, the unlatching actuator capable of moving the latch-engaging feature to thereby move the latch engaged therein between the engaged position and the disengaged position; and an opening mechanism including an opening actuator and a top portion-engaging member, the top portion-engaging member engaging the top portion of the received cassette, the opening actuator capable of moving the top portion-engaging member to thereby move the top portion of the received cassette engaged thereby between the closed and the open position.

[0008] Variations of this aspect of the invention may include one or more of the following features. The securing mechanism includes a plurality of clamping members, one of the clamping members being movable relative to another of the clamping members between an open and a closed position, the clamping members being arranged to receive the cassette when the one clamping member is in the open position and to secure the bottom portion of the received cassette when the one clamping member is in the closed position. The securing mechanism includes a biasing member mounted to bias one of the clamping members toward the closed position. The securing mechanism includes a suction cup and vacuum source for providing a vacuum pressure to the suction cup, the suction cup arranged to contact and apply the vacuum pressure to the bottom portion of the received cassette, wherein the bottom portion of the received cassette is thereby secured. The latch engaging feature includes a block defining a latch receiving slot. The block further defines a taper at one end of the receiving slot, the taper guiding a latch of the cassette into the receiving slot as the cassette is received in the holding mechanism. The unlatching mechanism further includes a variable mounting arm coupling the latch-engaging feature to the unlatching actuator, wherein the variable mounting arm allows the latch-engaging feature to adjust as necessary relative to the unlatching actuator to engage the latch of the received cassette. The top portion-engaging member includes a suction cup and vacuum source for providing a vacuum pressure to the suction cup. The automated cassette opening device further includes a sensor for sensing an engagement of the suction cup with the top portion of the received cassette. The opening mechanism includes a pivot arm arranged to be rotated by the opening actuator to move the top portion of the received cassette between the closed and the open position. The opening mechanism further includes a sensor for sensing a position of the opening actuator. The automated cassette opening device further includes a sensor for sensing a presence of the top portion of the received cassette in the open position.

[0009] In another aspect the invention provides a method of automatically opening a cassette, the cassette having a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position. The method includes securing the bottom portion of the cassette; engaging the latch; moving the latch to the disengaged position; engaging the top portion of the cassette; moving the top portion of the cassette to the open position.

[0010] In another aspect, the invention provides a method of automatically opening a cassette, the cassette having a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position. The method includes securing the bottom portion of the cassette, engaging the latch, moving the latch to the disengaged position, engaging the top portion of the cassette and moving the top portion of the cassette to the open position.

[0011] Variations of this aspect of the invention may include one or more of the following features. The method further includes sealing and filtering an environment within which the cassette is located prior to the step of moving the top portion of the cassette to the open position. The method further includes sealing and filtering the environment within which the cassette is located prior to the step of moving the latch to the disengaged position. The method further includes automatically moving the top portion of the cassette to the closed position after said step of moving the top portion o the cassette to the open position. The method further includes maintaining a sealed and filtered environment until after said step of moving the top portion of the cassette to the closed position.

[0012] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

[0013]FIG. 1 is an unscaled, schematic view of a typical cassette for use with the present invention.

[0014]FIG. 2 is an unscaled, perspective view of an apparatus of the invention, for automatically opening the cassette of FIG. 1.

[0015]FIG. 3 is an isolated view of the unlatch mechanism of the apparatus of FIG. 2.

[0016]FIG. 4 is an enlarged view of the unlatch mechanism of FIG. 3, viewed from a different perspective and with a cover removed.

[0017]FIG. 5 is an enlarged, cutaway view of the cassette lid opening mechanism of the apparatus of FIG. 2 with the housing cut away.

[0018] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0019] A typical means of storing and protecting a photomask for subsequent use, e.g., in the production of semiconductors, is to place the photomask in a protective cassette. Referring to FIG. 1, one typical transport cassette 10, often referred to as a “clamshell” type cassette has a pair of hinges 12 on one side 14 that pivotally connect the top portion 16 to the bottom portion 18 to allow the cassette to be opened. Two latch mechanisms 20 and 22 located on a front side 24 of bottom portion 18 opposite hinges 12 are provided for securing the cassette in the closed position. Latch mechanisms 20 and 22 operate by sliding laterally away from each other to disengage corresponding detents (not shown) of top portion 16, thereby releasing the top portion so that it can be pivotally swung away from bottom portion 18. Each latch mechanism has a protruding feature 25 extending in a direction away from side 24. An exemplary cassette of this type is commercially available from the Toppan Printing Co., LTD, of Tokyo, Japan. The walls of such cassettes are usually transparent so that an operator or fiber optic sensor can detect the presence or absence of a photomask within the cassette while it is closed.

[0020] Referring now to FIG. 2, an automated cassette opening device 30 includes a cassette receiving nest portion 40, an unlatching mechanism 70, and a lid opening mechanism 110, all three of which are mounted on a chassis supported by legs 32. Device 30 is typically positioned within a manufacturing cell 4, shown schematically as a rectangle in FIG. 2, that is accessible through a door 5, but remains substantially sealed from the outside environment when door 7 is in a closed position (shown in dashed lines). Manufacturing cell 4 has equipment (not shown) for handling a photomask, such as one contained within the above-described cassette 10, and also has an air filtration system for removing potentially harmful contaminants from circulation within the closed environment. A central processor 6 having a user interface 7 is provided for receiving input signals from various sources such as an operator, the photomask handling equipment and from device 30 as further described below.

[0021] Cassette nest portion 40 has three stationary supports 42 a, 42 b and 42 c and a crowding support 44 mounted, one each, at the four corners of rectangular base 46. Each stationary support 42 a, 42 b and 42 c has a corresponding cassette receiving surface 48 a, 48 b and 48 c, and a relatively perpendicular cassette securing surface 50 a, 50 b and 50 c. While crowding support 44 also has a cassette receiving surface 48 d, it has a relatively perpendicular “C” shaped securing surface 51 for engaging both intersecting surfaces of a corner of the cassette bottom portion. Cassette receiving surfaces 48 a, 48 b, 48 c and 48 d are coplanar for receiving the bottom surface of a cassette 10 placed in nest portion 40 while cassette securing surfaces 50 a, 50 b, 50 c and 51 act to prevent lateral motion of a received cassette. Crowding support 44 is slidably mounted on planar base 46 so that it is movable along a direction A extending radially outward from a center region 47 of the base and it is spring-biased inwardly towards center region 47. In a relaxed position, crowding support 44 is arranged so that placement of a cassette 10 into nest portion 40 with its bottom surface in contact with all four of support surfaces 48 a, 48 b, 48 c and 48 d necessarily requires a corresponding corner of the cassette to engage securing surface 51 forcing support 44 to slide outwardly, away from the center of base 46 against the resistance of the spring mount (not shown). When released, crowding support 44 acts to apply pressure against the bottom portion of a received cassette 10, laterally securing the cassette between securing surfaces 50 b, 50 c and 51 of supports 42 b, 42 c and 44, respectively and unlatch mechanism 70.

[0022] Each of the three stationary supports 42 has a fiber optic sensor (not shown) positioned to detect and send a corresponding signal confirming the presence of a fully seated received cassette in the nest portion. For example, if a cassette is fully seated on only two of the three stationary supports 42 a, 42 b and 42 c, the fiber optic sensor of the support on which the cassette is not fully seated will detect the cassette's absence, and a corresponding signal will be sent to controller 6 through conduit 9, controller 6 thereafter alerting an operator of the misload and/or disabling the opening device 30 from further operation until the cassette is properly seated.

[0023] A flexible suction cup 52 is positioned in the center region 47 of base 46 and has an interior region 54 that can be evacuated by an attached vacuum source (not shown). An upper portion 53 of resilient cup 52 is arranged to be necessarily deflected by a fully seated cassette received on surfaces 48 a, 48 b, 48 c and 48 d of supports 42 a, 42 b, 42 c and 44, respectively. This deflecting contact of the bottom surface of the received cassette and upper portion 53 is sufficient to effectively seal interior region 54 of suction cup 52 from the external atmosphere. Subsequent evacuation of interior region 54 by the vacuum source creates a pressure force that resists any upward motion of cassette bottom portion 18 when top portion 16 is pivoted to an open position. A vacuum sensor 55 attached to suction cup 52 sends a signal confirming that the suction cup has properly engaged and formed a seal against the cassette bottom to complete the vacuum circuit before the lid opening mechanism 110 is actuated as described below.

[0024] A photomask presence sensor 56 is positioned on base 46 adjacent suction cup 52 to detect the presence of a photomask within a received transparent cassette 10 and to send a corresponding signal to controller 6, which in turn notifies an operator, aborts further photomask unloading operations and/or controls device 30 and other equipment within manufacturing cell 4 to load the received cassette with a photomask that is already present within the cell.

[0025] Unlatching mechanism 70 is mounted adjacent one edge 72 (FIG. 2) of base 46. Referring now also to FIGS. 3 and 4, mechanism 70 has a parallel jaw actuator 74 capable of simultaneously laterally driving two jaws having slidably attached latch receptacle devices 76 and 78 between open and closed positions, devices 76 and 78 being relatively further from one another in the open position. Latch receptacle devices 76 and 78 are symmetrically identical, thus the internal structure of only device 76 is illustrated in FIG. 4 (cover removed) and the following description applies to both devices 76 and 78. Receptacle device 76 has a block 80 mounted to protrude toward center region 47 of base 46. Block 80 has a notch 82 with a tapered opening 84, positioned for receiving and guiding protrusion 25 of latch 22 into notch 82 when a cassette 10 is properly received in nest portion 40.

[0026] Block 80 is mounted on a receptacle slide 87, which is in turn attached to an arm 88 that is resiliently mounted to receptacle base 86 of actuator jaw 77. Arm 88 is secured to receptacle base 86 between two compliance springs 90 and 92 (each shown with one end 90 a and 92 a, respectively, unattached) which allow for tensioned, adjusting movement of block 80. This arrangement allows for fine-tuning of the lateral position of notch 82 and accommodates overtravel of unlatching mechanism 70 without damaging an engaged latch of a cassette to be opened. Compliance spring 90 is connected to receptacle base 86 by way of threaded eyelets 94 a and 94 b while compliance spring 92 is similarly connected between threaded eyelets 96 a and 96 b. Threaded eyelets 94 a, 94 b, 96 a and 96 b can be adjusted to alter the nominal lateral position of block 80 so that the relative lateral position of notch 82 can be fine tuned to match the lateral location of corresponding latch protrusion 25 of a nominal cassette to be loaded in nest portion 40. Additionally, compliance springs 90 and 92 allow for overtravel of actuator jaws 75 and 77 without damaging latches 20 and 22 of a received cassette 10 when the latches are engaged in notches 82. Because it is necessary for latches 20 and 22 to be moved to their fully open positions in order to disengage top portion 16, and because the relative spacing of latch protrusions 25 varies from cassette to cassette, it is important that latch opening mechanism 70 be capable of laterally displacing latches 20 and 22 slightly beyond a nominal or design latch open spacing dimension. Compliance springs 90 and 92 allow for such overtravel by resiliently compressing and stretching, respectively, to increase resistance against actuator jaw movement while allowing block 80 to remain stationary at the limit of an engaged cassette latch's movement.

[0027] Parallel jaw actuator 74 is mounted to a mounting bracket 71 which is in turn connected to base 46. Proximity sensors 98 and 99 are also mounted on mounting bracket 71 to detect an open or closed position of latch receptacle devices 76, 78 and to send corresponding signals to controller 4 which then alerts an operator and/or disables continued operation of cassette opening device 30 in the event the cassette has not been successfully unlatched.

[0028] The above described structure enables unlatching mechanism 70 to accommodate cassettes despite slight variations in the relative spacing of latch protrusions 25 from one cassette to another. This is accomplished by tapered openings 84 which guide slightly misaligned latch protrusions 25 into notches 82 and by compliance springs 90 and 92 which allow for adjusting movement of blocks 80. Furthermore, when a misalignment of latch protrusions 25 with notches 82 appears to be a consistent trend, the nominal positions of blocks 80 can be adjusted by appropriately turning threaded eyelets 94 a, 94 b, 96 a and 96 b.

[0029] Referring now also to FIG. 5, opening mechanism 110 includes an opening arm 112 pivotally mounted adjacent an edge 113 of base 46 opposite unlatch mechanism 70 (FIG. 2). Arm 112 is coupled by way of first linkage 114 and second linkage 116 to a rotary actuator 118 capable of pivoting arm 112 between a closed position and an open position (as indicated by arrow B in FIG. 5). A suction cup 120 extends from free end 122 of arm 112 toward the center of base 46. A cavity 124 defined by the internal surface of suction cup 120 is connected by way of channel 126 and hose 128 to a vacuum source 130 capable of evacuating the cavity. Sensors 131 and 132 are provided adjacent linkage 114 for detecting the position of opening arm 112 in the up or down position and for sending a corresponding signal. A vacuum sensor 133 (FIG. 2) coupled to suction cup 120 sends a signal confirming that the suction cup has engaged and sealed against the cassette top portion 16 to complete the vacuum circuit before the lid opening mechanism 110 is actuated. Additionally, a cassette top open sensor 134 is mounted on a support 135 to detect the presence of cassette top portion 16 when opening arm 112 has been actuated to open the cassette. Sensor 134 sends a signal indicating that the cassette has been successfully opened and also signals e.g., an inadvertent or intentional movement of the opened top portion 16 to the closed position.

[0030] To operate the cassette opening device 30, an operator initially opens door 5 of manufacturing cell 4 and enters to place a closed cassette into nest portion 40. Positioning the cassette above base 46 with hinges 12 facing opening arm 112 which is in its open position (as illustrated), the operator contacts a corner of the cassette against surface 51 of slidable support 44 and applies appropriate pressure away from center region 47 of base 46 to move support 44 outward against its spring-biased mount. Subsequently, the operator lowers the cassette so that its bottom surface contacts each of co-planar support surfaces 48 a, 48 b, 48 c and 48 d. This seating of the cassette causes latch protrusions 25 to enter notches 82 of latch device 40 while bottom portion 18 of the cassette is secured against lateral and rotational movement by the action of crowding support 44 against stationary supports 42 b and 42 c and blocks 80 of unlatching mechanism 70.

[0031] With the cassette seated in nest 40, the operator exits manufacturing cell 4 and, after closing door 5 to reestablish the closed environment of the cell, activates controller 6 by way of user interface 7 to initiate the cassette opening process. Alternatively the cassette opening process is initiated automatically. In this case, a sensor (not shown) is provided to detect the closing of door 5 and to correspondingly signal controller 6. Having also received signals from the sensors of stationary supports 42 a, 42 b and 42 c confirming the presence of the received cassette, controller 6 initiates the cassette opening process automatically. In either case, the cassette opening process begins with the controller sending a signal to activate and apply a vacuum force through suction cup 54 to secure cassette bottom portion 18 against vertical movement. With cassette bottom portion 18 secured, controller 6 signals lateral actuator 74 to move blocks 80 away from one another; consequently moving engaged cassette latches 22 and 24 toward their open positions. Controller 6 then signals rotary actuator 118 to pivot opening arm 112 toward its closed position until resilient suction cup 120 deflects and seals against the outer surface of top portion 16 of cassette 10. Controller 6 activates vacuum source 130, thereby creating a pressure within suction cup 120 that operably secures free end 122 of opening arm 120 to cassette top portion 16. Finally, controller 6 activates rotary actuator 118 to pivot arm 120 toward its open position, thereby rotating engaged cassette top portion 16 about hinges 12 to its open position relative to cassette bottom portion 18.

[0032] With the cassette in its open position, a photomask resting within the bottom portion of the cassette can then be manipulated, used and replaced within the cassette by, e.g., other automatic equipment within manufacturing cell 4. Cassette opening device 30 can then operate in a reverse manner to that described above to close the cassette, thereby protecting the contained photomask before it is removed from the manufacturing cell.

[0033] Another feature of automated device 30 includes a fiber optic sensor 140 (FIG. 2) located adjacent edge 113 of base 46 for detecting a cassette that has been loaded “upside down”, i.e., with its top portion 16 facing base 46. Optic sensor 140 is positioned on base 46 between crowding support 44 and one of stationary supports 42 such that it will detect a properly loaded cassette that is placed in nest portion 40 with its latch protrusions engaged within notches 82 of unlatching mechanism 70. Having detected a properly loaded cassette, sensor 140 sends a corresponding signal to controller 6 confirming that operation of cassette opening device 30 may proceed. However, when a cassette is loaded upside down, latches 20, 22, which are disposed on bottom portion 18 of cassette 10, will not contact the inwardly facing surface of blocks 80 of unlatching mechanism 70, i.e., latches 20, 22 will lie above blocks 80 and the entire misloaded cassette will be shifted toward unlatch mechanism 70 by crowding support 44. Sensor 140 will not detect the presence of the cassette and will not send a signal confirming the presence of a properly loaded cassette. Controller 6 is preprogrammed to abort further operation of cassette opening device 30 without receipt of this signal and an attempted opening of the misloaded cassette will be avoided.

[0034] Automated cassette opening device 30 offers many advantages over manual opening of cassettes. As mentioned above, the photomasks stored within the cassettes are often used within enclosed manufacturing cells equipped with air filtration systems in an attempt to avoid any contaminants from fouling the functionality of the photomasks. Where cassettes are placed within these manufacturing cells and opened manually, it is typically necessary for the cell to be in an open condition while the photomask is exposed. For instance, in the typical manual cassette opening operation, an operator opens a door to the manufacturing cell, reaches his or her hand into the cell to place a photomask-containing cassette, unlatches and opens the cassette and then removes his or her hand from the cell. Only then does the operator close the cell to reestablish the sealed, filtered environment. Thus, the photomask in the open cassette is momentarily exposed to contaminants that may enter the cell while the doors are open. One common source of such contaminants is the operator's cassette-opening hand or tool, which is temporarily, but necessarily, present within the cell while the photomask is exposed during the manual cassette opening operation.

[0035] By using an automated cassette opening device, e.g., as described above, opportunities for contamination of the photomask are greatly reduced. Such an automated cassette opening device, arranged within a filtered manufacturing cell, can be loaded by an operator with a photomask containing cassette. With the cassette in its closed condition, the operator can exit and seal the cell allowing the filtering system to clear any contaminants introduced during the cassette loading process. Subsequently, the automated cassette opening device can open the cassette to expose the photomask for further automated handling and use within the cell. Upon completion of use of the photomask, it can be placed back within the cassette by other automated equipment of the manufacturing cell, and the automatic cassette opening device can close the cassette, without ever having to open the cell itself.

[0036] While we have described one exemplary embodiment in detail, a number of modifications may be made without departing from the spirit and scope of the invention. For example, the suction cup/vacuum combination and/or the crowding/stationary support arrangement used for securing the cassette bottom portion against vertical, lateral and rotational movement during operation of the cassette opening device could be replaced with mechanical jaws, hooks, clamps or other devices arranged to secure the cassette bottom portion. Likewise, the suction cup/vacuum combination used to secure the engagement of the free end of opening arm with the cassette top portion could be replaced with a hook, clasp or other fastening element to releasably engage the cassette top. Accordingly, other embodiments are within the scope of the following claims. 

What is claimed is:
 1. An automated cassette opening device for opening a cassette having a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position, the device comprising: a holding mechanism for receiving the cassette and securing the bottom portion of a received cassette; an unlatching mechanism including an unlatching actuator coupled to a latch-engaging feature, the latch-engaging feature engaging the latch of the received cassette, the unlatching actuator capable of moving the latch-engaging feature to thereby move the latch engaged therein between the engaged position and the disengaged position; and an opening mechanism including an opening actuator and a top portion-engaging member, the top portion-engaging member engaging the top portion of the received cassette, the opening actuator capable of moving the top portion-engaging member to thereby move the top portion of the received cassette engaged thereby between the closed and the open position.
 2. The automated cassette opening device of claim 1, wherein the holding mechanism comprises a plurality of clamping members, one of the clamping members being movable relative to another of the clamping members between an open and a closed position, the clamping members being arranged to receive the cassette when the one clamping member is in the open position and to secure the bottom portion of the received cassette when the one clamping member is in the closed position.
 3. The automated cassette opening device of claim 2, wherein the holding mechanism includes a biasing member mounted to bias said one clamping member toward the closed position.
 4. The automated cassette opening device of claim 1, wherein the holding mechanism comprises a suction cup and vacuum source for providing a vacuum pressure to the suction cup, the suction cup arranged to contact and apply the vacuum pressure to the bottom portion of the received cassette, wherein the bottom portion of the received cassette is thereby secured.
 5. The automated cassette opening device of claim 1, wherein the latch engaging feature includes a block defining a latch receiving slot.
 6. The automated cassette opening device of claim 5, wherein the block further defines a taper at one end of the receiving slot, the taper guiding a latch of the cassette into the receiving slot as the cassette is received in the holding mechanism.
 7. The automated cassette opening device of claim 6, wherein the unlatching mechanism further includes a variable mounting arm coupling the latch-engaging feature to the unlatching actuator, wherein the variable mounting arm allows the latch-engaging feature to adjust as necessary relative to the unlatching actuator to engage the latch of the received cassette.
 8. The automated cassette opening device of claim 1, wherein the top portion-engaging member includes a suction cup and vacuum source for providing a vacuum pressure to the suction cup.
 9. The automated cassette opening device of claim 8, further comprising a sensor for sensing an engagement of the suction cup with the top portion of the received cassette.
 10. The automated cassette opening device of claim 9, wherein the opening mechanism includes a pivot arm arranged to be rotated by the opening actuator to move the top portion of the received cassette between the closed and the open position.
 11. The automated cassette opening device of claim 10, wherein the opening mechanism further comprises a sensor for sensing a position of the opening actuator.
 12. The automated cassette opening device of claim 11 further comprising a sensor for sensing a presence of the top portion of the received cassette in the open position.
 13. A method of automatically opening a cassette, the cassette having a top portion hingedly fixed to a bottom portion, the top portion being pivotable between a closed and an open position relative to the bottom portion, the cassette having a latch movable between an engaged position for securing the top portion to the bottom portion when the cassette is in the closed position and a disengaged position for allowing the top portion to pivot relative to the bottom portion to the open position, the method comprising: securing the bottom portion of the cassette; engaging the latch; moving the latch to the disengaged position; engaging the top portion of the cassette; moving the top portion of the cassette to the open position.
 14. The method of claim 13 further comprising sealing and filtering an environment within which the cassette is located prior to said step of moving the top portion of the cassette to the open position.
 15. The method of claim 14 further comprising sealing and filtering the environment within which the cassette is located prior to said step of moving the latch to the disengaged position.
 16. The method of claim 14 further comprising automatically moving the top portion of the cassette to the closed position after said step of moving the top portion of the cassette to the open position.
 17. The method of claim 16, further comprising maintaining a sealed and filtered environment until after said step of moving the top portion of the cassette to the closed position. 